Adaptive digital predistortion linearizer for power amplifiers in military UHF satellite
نویسنده
چکیده
The existing UHF Satellite Communications (SATCOM) transponders used for military applications use efficient, saturated power amplifiers, which provide one earth-coverage antenna beam. The amplifier is dedicated to small frequency band and only handles a few carriers simultaneously. The communications capacity needed to support future military forces on the move will require satellite payload power amplifiers to support hundreds of channels simultaneously, with the channels spread over the entire military UHF SATCOM band. To meet the capacity requirements and simultaneously meet the out-of-band emission, power amplifiers will have to be highly linear. The high-efficiency, ultra-linear power amplifier architecture proposed to support the requirements can only be met by use of linearity improvement techniques. The literature search revealed many power amplifier linearity improvement techniques. Each technique was reviewed to determine its suitability for the proposed power amplifier architecture. The adaptive digital predistortion technique was found to be the most suitable in terms of bandwidth, correction achievable, and complication.
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